Table 3.

CHD discrimination among WHI women who have ever been pregnant for established CHD risk factors, reproductive factors and combined models.

Model	C-statistic (n=72,982)	C Difference from Established Risk Factor Model	Bootstrap 95% CI for difference from Established Risk Factor Model (n=72,982)
Age + reproductive risk factors*	0.675
Established risk factors†	0.726
Established risk factors + age at first birth	0.728	0.0019	(0.0010, 0.0032)
Established risk factors + number of stillbirths	0.727	0.0005	(0.0001, 0.0013)
Established risk factors + number of miscarriages	0.727	0.0010	(0.0004, 0.0020)
Established risk factors + breast feeding	0.726	0.0001	(−0.00002, 0.0005)
Established risk factors + significant reproductive factors‡	0.730	0.0033	(0.0022, 0.0051)

^*Reproductive risk factors include menstrual irregularity, age at first birth, still births, miscarriages, and breastfeeding ≥ 1 month.

^†Established risk factors modeled include age, high cholesterol requiring pills, currently taking pills for hypertension, log of systolic blood pressure, current smoker, diabetes.

^‡Significant reproductive risk factors include age at first birth, still births, miscarriages, and breastfeeding ≥ 1 month.